Abstract: A multi-axially forged mono-bloc piston includes a lower crown part forged of steel and including a pair of pin bosses and an integral skirt formed as one piece with the pin bosses 20. The lower crown part is friction welded to an upper crown part to form at least one closed oil gallery within the piston head. The lower crown part is forged in the longitudinal direction of the piston as well as laterally to impart longitudinal and laterally forged features of the piston. The laterally forged features may comprise undercut recesses formed in the piston skirt to reduce material in the overall piston structure. The lateral forging may also result in the piston skirt portion being discoupled from the piston head by laterally forged slots formed in the lower crown part 14 between the skirt and head.

Abstract: A multi-axially forged mono-bloc piston includes a lower crown part forged of steel and including a pair of pin bosses and an integral skirt formed as one piece with the pin bosses 20. The lower crown part is friction welded to an upper crown part to form at least one closed oil gallery within the piston head. The lower crown part is forged in the longitudinal direction of the piston as well as laterally to impart longitudinal and laterally forged features of the piston. The laterally forged features may comprise undercut recesses formed in the piston skirt to reduce material in the overall piston structure. The lateral forging may also result in the piston skirt portion being discoupled from the piston head by laterally forged slots formed in the lower crown part 14 between the skirt and head.

Abstract: A piston particularly adapted for heavy-duty diesel engine applications is fabricated from separate parts having circumferentially extending joining surfaces that are heated prior to bonding to an elevated temperature sufficient to enable bonding of the joining surfaces, and thereafter the joining surfaces brought into contact with one another and twisted to attain a permanent metallurgical weld at the interface of the joining surfaces.

Abstract: A piston particularly adapted for heavy-duty diesel engine applications is fabricated from separate parts having circumferentially extending joining surfaces that are heated prior to bonding to an elevated temperature sufficient to enable bonding of the joining surfaces, and thereafter the joining surfaces brought into contact with one another and twisted to attain a permanent metallurgical weld at the interface of the joining surfaces.

Abstract: A piston particularly adapted for heavy-duty diesel engine applications is fabricated from separate parts having circumferentially extending joining surfaces that are heated prior to bonding to an elevated temperature sufficient to enable bonding of the joining surfaces, and thereafter the joining surfaces brought into contact with one another and twisted to attain a permanent metallurgical weld at the interface of the joining surfaces.

Abstract: A wrist pin is provided comprising a generally cylindrical body having a longitudinal axis. The body is fabricated of at least two metallic parts joined to one another at a weld joint. In joining the two parts to one another, a pair of laterally spaced support ribs are defined and an internal chamber is further defined between the support ribs.

Abstract: A corrosion resistant piston for use in an exhaust gas recirculation diesel engine. The piston includes a crown portion having ring grooves formed around a periphery of the crown portion. The ring grooves are separated by ring lands. The piston also includes a piston rod connecting portion that extends from the crown portion. The piston is made of steel and includes an electroless coating of nickel having a maximum thickness of 8 micrometers.

Abstract: A piston assembly for heavy duty diesel engine applications comprises a piston having pin bosses formed with pin bores for the accommodations of a wrist pin. The wrist pin is fabricated of steel and is extendable through the small end bore of a steel connecting rod and the bores of the piston body for coupling the piston body to the connecting rod. In lieu of a conventional Cu—Pb—Sn bushing usually pressed into the small end bore, a coating of manganese phosphate is applied to either the pin or small end bore of the connecting rod and pin bosses to provide the necessary tribological properties therebetween. The porous coating absorbs and entraps lubricating oil, creating a still lubricant squeeze film between the steel running surfaces under heavy load.

Abstract: A piston for diesel engines includes a piston body having a closed oil gallery and a pair of pin bosses with axially aligned pin bores. The inner faces of the pin bosses are separated from one another by an intervening space between the pin bosses for receiving the upper end of a connecting rod, which has associated outer faces adjacent the inner faces of the pin bosses. Oil passages extend from the gallery and open to the inner faces of the pin bosses for providing direct lubrication to the inner faces.

Abstract: A corrosion resistant piston for use in an exhaust gas recirculation diesel engine. The piston includes a crown portion having ring grooves formed around a periphery of the crown portion. The ring grooves are separated by ring lands. The piston also includes a piston rod connecting portion that extends from the crown portion. The piston is made of steel and includes an electroless coating of nickel having a maximum thickness of 8 micrometers.

Abstract: A piston for diesel engines includes a piston body having a closed oil gallery and a pair of pin bosses with axially aligned pin bores. The inner faces of the pin bosses are separated from one another by an intervening space between the pin bosses for receiving the upper end of a connecting rod, which has associated outer faces adjacent the inner faces of the pin bosses. Oil passages extend from the gallery and open to the inner faces of the pin bosses for providing direct lubrication to the inner faces.

Abstract: A piston for diesel engines includes a piston body formed with a closed oil gallery and a pair of pin bosses having axially aligned pin bores whose surfaces are spaced from one another about their circumference across an intervening gap between the pin bosses. The pin bore surfaces are each formed with a recess which extends in the axial direction of the pin bores across the full width of each of the pin bore surfaces. An oil passage leads from the gallery to each of the recesses and feeds the recesses with lubricating oil from the gallery. The recesses act as retention basins or reservoirs which collect and supply the pin bore surfaces with lubricating oil during the fall cycle of the piston.

Abstract: A ferrous cylinder liner for use in diesel engines equipped with exhaust gas recirculation has at least a portion of its inner surface covered by an electroless coating of nickel. The coating has a maximum thickness of 8 micrometers and presents a continuous, non-porous barrier which protects the ferrous liner against attack from the corrosive EGR environment.

Abstract: An articulated piston includes a crown and a separate skirt joined in articulated manner to the pin bosses of the crown by a wrist pin. The skirt has opposing thrust surfaces which contact the wall of a cylinder bore of an engine when the piston experiences side loading during operation. The thrust surfaces have a vertical profile which is generally symmetrical about a center plane containing the axis of a pin bore of the skirt. The profile includes tapered end sections and a wide, shallow central depressed region. Under normal operation, the depressed region channels lubricant to the pin bores. The twin peaked profile distributes side loads and stress above and below the pin bore plane and under heavy load, the depressed region bows outwardly presenting a flat, full contact surface between the peaked regions for decreasing the wear load on the thrust surfaces.

Abstract: A closed gallery piston includes a piston body having a closed gallery for cooling oil defined in part by a bottom wall and outer wall of the piston body. At least one oil hole is formed in the bottom wall to accommodate a flow of cooling oil within the gallery. The bottom wall is locally thickened in the area bordering the oil hole with an oil hole boss to reinforce the bottom wall in the vicinity of the oil hole. The oil hole boss preferably joins with the outer wall to provide added structural integrity to the piston body at the juncture between the outer wall and bottom wall near the oil hole.

Abstract: An articulated piston includes a crown and a separate skirt joined in articulated manner to the pin bosses of the crown by a wrist pin. The skirt has opposing thrust surfaces which contact the wall of a cylinder bore of an engine when the piston experiences side loading during operation. The thrust surfaces have a vertical profile which is generally symmetrical about a center plane containing the axis of a pin bore of the skirt. The profile includes tapered end sections and a wide, shallow central depressed region. Under normal operation, the depressed region channels lubricant to the pin bores. The twin peaked profile distributes side loads and stress above and below the pin bore plane and under heavy load, the depressed region bows outwardly presenting a flat, full contact surface between the peaked regions for decreasing the wear load on the thrust surfaces.

Abstract: The invention relates to a piston head (10) of a piston for an internal combustion engine, in particular for diesel engines, comprising an upper part (12) having a piston crown extending substantially perpendicularly to the longitudinal axis (A) of a piston, and a lower part (14) connected with the upper part (12) and having two pin bosses (26a, b), the mutually facing sides of which are arranged at a mutual distance from one another, the pin bosses (26a, b) each comprising a pin hole (40a, 40b) extending perpendicularly to the longitudinal axis (A) of the piston and in each case aligned with the other and a cavity being formed in the junction area (28a, 28b) of the upper part (12) and the lower part (14), which cavity adjoins the piston crown (16) on the pin boss side and opens into the area between the pin bosses (26a, b).

Abstract: A multi-axially forged mono-bloc piston includes a lower crown part forged of steel and including a pair of pin bosses and an integral skirt formed as one piece with the pin bosses 20. The lower crown part is friction welded to an upper crown part to form at least one closed oil gallery within the piston head. The lower crown part is forged in the longitudinal direction of the piston as well as laterally to impart longitudinal and laterally forged features of the piston. The laterally forged features may comprise undercut recesses formed in the piston skirt to reduce material in the overall piston structure. The lateral forging may also result in the piston skirt portion being discoupled from the piston head by laterally forged slots formed in the lower crown part 14 between the skirt and head.

Abstract: The piston sleeve has a radial positioning surface adjacent to the top surface and an axial positioning surface separated from radially positioning surface by a coolant contact surface. A piston bore extending the length of the piston sleeve is machined to form a non-cylindrical bore. The sleeve is compressed by applying force to the top surface and to the axial positioning surface. The piston sleeve is also heated to a normal working temperature. The compression force and the force due to thermal expansion deforms the piston sleeve and changes the non-cylindrical bore into a substantially cylindrical bore.

Abstract: This invention relates to a high temperature-resistant piston head. The piston head includes a first portion formed of a first material of heat-resistant steel alloy and the second portion is formed of a second a material of steel alloy that may be the same or may or different from the first material. The first and second portions are joined by a friction weld to form the assembled piston head. The heat-resistant steel alloy includes about 0.1 to about 0.5 wt % carbon, up to about 0.6 wt % manganese, about 4.0 to about 6.0 wt % chromium, about 0.45 to about 0.65 wt % molybdenum, up to about 0.5 wt % nickel and the balance iron and incidental impurities. In one form the second material includes about 0.30 to about 0.55 wt % carbon, about 0.4 to about 1.10 wt % manganese, about 0.40 to about 1.25 wt % chromium, about 0.15 to about 0.45 wt % molybdenum, up to about 0.4 wt % silicon, up to about 2 wt % Ni and greater than about 90 wt % iron.